Mushroom Log Inoculation-Some Things We’ve Learned

We are excited to get started growing mushrooms this year.  We just finished inoculating a little over 100 logs with shiitake and oyster mushroom spawn.  Now the logs will sit in our woods and quietly do their thing.  We won’t know until 2016 if we have been successful or not.  We chose 100 logs as a number that seemed big enough to have more than our personal needs fulfilled, but not too risky or daunting for a first try.

There are many good sources of information out there with step by step instructions about doing outdoor log production of mushrooms.  We got a lot of inspiration and instruction from the new book Farming the Woods.  Rebecca also had the chance to do a full day workshop with Steve Gabriel (co author of the book) which was useful in picking up a few more tidbits of info that were not in the book.  Cornell Extension also has a you tube channel with many helpful videos about shiitake growing as well as other aspects of cultivating forest products here. We thought it might be more helpful for us to share some tid bits that we learned in this step of the process that might be useful to others just getting started in mushroom cultivation.

Logs

Though the most recommended type of logs for shiitake cultivation are oak or sugar maple, we chose to use primarily birch because that is what we have the most of on our property.  While the “Farming the Woods” book does not list white birch as a recommended species, that was one lucky piece of information garnered from the workshop.  Steve Gabriel said that should be updated in the book as he has since heard from several experienced shiitake growers that it works fine- so we went for it.

Logs need to be cut in the winter while the tree is dormant.  We didn’t start cutting the appropriate logs until there was at least 3 feet of snow on the ground.  We dragged the logs out of the woods by sled and it was a ton of work.  Next year we will cut logs earlier in the winter before we have lots of snow hopefully.

Shiitake Strains

There are different varieties of shiitake. Some will fruit in a wide range of temperatures, but need to be soaked in tub of water in order to stimulate the mushrooms to burst forth. Other varieties are not affected by soaking, but instead take their cues from temperature. We chose to start with two cold varieties and one wide range to have shiitakes throughout the season. Cold varieties can be grown on larger logs because they do not need to be soaked or moved around, which would be too heavy with logs over 6 inches in diameter. So, when choosing our logs we went with big ones for the cold varieties to save our backs, and they should also last longer. Also, when ordering all your materials, try to plan ahead a month in advance because it takes a few weeks to get your order delivered. We found out the hard way that you won’t get your order the next weekend!

Drilling the Logs 

Using an angle grinder is super duper way faster than a drill.  We got the appropriate sized drill bit and adapter as well as all of our spawn and materials from Field and Forest Products.  One thing we didn’t realize is that all angle grinders are not uniform in spindle size and therefore won’t work with the adapter.  We had borrowed one, then wasted a bunch of time trying to find an adapter piece.  We ended up just buying a new angle grinder in the end.  Probably a good thing to have anyway.  If you us the adapter that field and forest sells you will need a 5/8 ” spindle on your angle grinder.

Spawn Tools

We used sawdust spawn and the tools that are sold to shove it in all those little holes in the logs come in two styles.  One is smaller and can be depressed with your thumb, making it possible to work the tool with one hand so that the other hand can steady and rotate the log.  There is another style of the tool also sold by Field and Forest that is much harder to press and requires two hands (unless you have giant hands) which makes the process much harder, especially with wonky logs with little branch stubs that won’t lie flat.

Wax

Keeping wax at the right temperature proved more challenging than expected.  We had planned on using a crock pot to keep cans of wax melted but it didn’t get hot enough to do the job.  Next we tried melting cans of wax in the house and then running out with it to apply to the logs, but it really needs to stay on the heat or it starts gunking up fast and then you use way more than needed and your paint brush gets gummed up.  We found a two part solution.  We made a quick rocket stove out of fire bricks that we could have nearby to keep a large can of wax melted and hot.  We then worked from little cans of wax that were kept warm over a candle (the invention of another friend trying out mushrooms for the first time).  We also found bristle brushes to work much better than foam brushes.  When a bristle brush gets gunky with cold wax you can dip it in the hot can of wax to melt (but not too long because you can burn the bristles right off, yes we did this).  If you dip the foam brush in the hot wax to degunk, it falls apart- not useful.

Also, in order for the wax to stick to logs they need to be dry, so bring them under cover a little in advance.

Tagging

To keep track of our varieties and inoculation years we stapled metal tags to the end of the logs.  You can buy aluminum tags from the supplier, but we chose to buy sheets of aluminum flashing, cut them into pieces, then scratch on the information with a pen.  Time will tell if the scratch remains legible.

Totems

Oyster mushrooms are supposed to grow well with the totem style of log inoculation where spawn in placed between chunks of log that are then stacked vertically.  We tried this with the Italian Oyster spawn we got.  One tip that we heard is not to cut your log chunks in advance and throw them all in a truck and move them to your location, because it is much harder than you think to line up the right chunks again. We found that this method uses a lot more spawn than the plugging holes style.  Also, our logs did not want to stay vertical (perhaps if they were a little wider in diameter they would work better).  After a few of them fell over we added new spawn, then secured each layer with a couple of nails set in at an angle and then propped the totems up with other log chunks.  We plan on digging holes and setting the totems about 8 inches into the ground to secure them.  In retrospect it would probably be best to wait until the ground is thawed to do this process so the totems can be stabilized in the ground from the beginning.

Help

We invited the local Permaculture Group to help us inoculate logs, thinking that others would like to learn the process and that many hands would make the job easier.  We learned that achieving both goals of education and efficient production work are hard to do at once.  In the future we will probably choose to do either a workshop, or just focus on getting logs filled, so that there are clear expectations.  The process goes pretty smoothly with just the two of us- perhaps the addition of one other person if we were to do more logs at once would be the right number to keep all steps in a good rhythm.

We hope to have delicious mushrooms popping out of our logs in 2016.  I’m sure we will learn much more along the way and will share our lessons, successes, or failures in the future.